Servicing my heating unit

I personally use a boiler system for everything around my home. The boiler provides an immense heating system. The heater stays within the basement and the heat travels through vents in my floor. Then my whole home can be heated by the boiler system. And also the boiler is hooked up as my warm water tank. It heats my home and in addition serves as a water unit. I got the boiler given it can serve two jobs together efficiently. Also a boiler is recognized as being super hardy and needing almost no maintenance. Well the other day I remarked that my boiler was making several weird noises. I had a feeling it would definitely break down on me. I knew I needed to get a professional to look at it. Then I realized I did not know who to call. Since the boiler serves for a water heater I feel like a plumber needs to check out it. It has to deal with piping and heating. But the boiler also serves as my home heating system. So that makes me believe a HVAC contractor also could help out the boiler system. What I did was deduce that which was the problem. Was it more on the plumbing issue or a HVAC difficulty? I deduced that it wasn’t the piping and heat for the shower. It was not some plumbing issue. The boiler made a rattling noise when it was heating my home. So that means I was required to call a HVAC provider to see my boiler. I think the HVAC business is able to handle it. I already called them and made the appointment.